The faster you spin it, the closer it is to coming apart. Why rev it if you don't have to? Mopar under-rated their engines. Build a second gen Race Hemi if you want rpm.
You're absolutely right...but if this is your argument, why not run a diesel that makes lots of torque way down low, peak power by 2.5k and revs to just 3k? Why run a big old V8 when a small, hotrodded 4cyl engine with a turbo does the job just as well and uses half the gasoline? Why run a carburetor when fuel injection keeps AFR within a much tighter range? Why run a manual transmission when an automatic is way easier on the rest of the drivetrain and faster too?
Why run an internal combustion engine when electric cars are so damn quick?
We do it because life is short and gas engines are FUN. :D
The sound and the feeling of revving a good breathing motor out is an absolute blast. A motor that is built to handle the revs and actually make power up there is a rare and fantastic experience.